In a lithium-ion secondary battery, an active material body, a conductive agent, and a binder are provided in a layer form on a current collector. The active material body, the conductive agent, the binder, and the current collector constitute a positive electrode or a negative electrode. In the lithium-ion secondary battery, performance as a battery is obtained by the movement of lithium ions (Li+) between the electrodes and the behavior of electrons flowing through the current collector.
In a common lithium-ion secondary battery, the positive electrode or the negative electrode is in a flat shape. In such a case, depending on the position in the electrode, there is a case where the difference between the speed at which the lithium ion arrives at the active material body and the speed at which the electron arrives at the current collector is significant. To use the electrode with good efficiency in the charging and discharging of the lithium-ion secondary battery, it is necessary to improve such a malfunction.